Genetic Mapping Flashcards
What are the 3 approaches to mapping?
Linkage-family based
Association-GWAS
Genome sequencing-whole genome or whole exome
Genes far apart on a chromosome: linked or not linked?
not linked
recombination frequency of 0 means…
completely linked
recombination frequency of 0.5 means…
unlinked
If 2 genes are far apart, is crossing over more or less likely?
more likely
The recombination frequency is 0.125. This means that out of 8 people….
one is a recombinant
What is map distance?
The observed recombination between loci.
Linkage disequilibrium
Non-random association between alleles in a population. Haplotype frequencies diverge from what is expected of allele frequencies.
What is a haplotype?
A group of genes within an organism that were inherited together from a single parent.
LOD score
- determines tightness of linkage
- tells you estimate of recombination frequency between two loci
- tells you how strong evidence is that there’s linkage between those loci
LOD > or = 3 indicates….
- Genes are linked
- Data observed 1000x more likely if linked than if by chance
What are the 2 types of association studies?
- case-control
2. cross-sectional/cohort
What do case-control studies compare?
Compares individuals with disease to a matching group of controls.
Odds Ratio (OR) formula
OR=ad/bc
If OR is 1, this means….
no association
